﻿using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace WenSkin.AES
{
    public class AesEnDe
    {
        public static string key = "qw6HjFG2HCZOIl0LXxt4UDofqN0RP5qi";
        public static string vector = "frhNcbk53xSzKsgf";
        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public static string AESEncrypt(string data)
        {
            return AESEncrypt(data, key, vector);
        }
        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public static string AESDecrypt(string data)
        {
            return AESDecrypt(data, key, vector);
        }

        /// <summary>
        /// AES加密
        /// </summary>
        /// <param name="Data">被加密的明文</param>
        /// <param name="Key">密钥</param>
        /// <param name="Vector">向量</param>
        /// <returns>密文</returns>
        public static string AESEncrypt(string Data, string Key, string Vector)
        {
            byte[] plainBytes = Encoding.UTF8.GetBytes(Data);

            byte[] bKey = new byte[32];
            Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);
            byte[] bVector = new byte[16];
            Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);

            byte[] Cryptograph = null; // 加密后的密文

            Rijndael Aes = Rijndael.Create();
            try
            {
                // 开辟一块内存流
                using MemoryStream Memory = new MemoryStream();
                // 把内存流对象包装成加密流对象
                using CryptoStream Encryptor = new CryptoStream(Memory,
                Aes.CreateEncryptor(bKey, bVector),
                CryptoStreamMode.Write);
                // 明文数据写入加密流
                Encryptor.Write(plainBytes, 0, plainBytes.Length);
                Encryptor.FlushFinalBlock();

                Cryptograph = Memory.ToArray();
            }
            catch
            {
                return null;
            }

            return Convert.ToBase64String(Cryptograph);
        }

        /// <summary>
        /// AES解密
        /// </summary>
        /// <param name="Data">被解密的密文</param>
        /// <param name="Key">密钥</param>
        /// <param name="Vector">向量</param>
        /// <returns>明文</returns>
        public static string AESDecrypt(string Data, string Key, string Vector)
        {
            byte[] original = null; // 解密后的明文
            try
            {
                byte[] encryptedBytes = Convert.FromBase64String(Data);
                byte[] bKey = new byte[32];
                Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);
                byte[] bVector = new byte[16];
                Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);



                Rijndael Aes = Rijndael.Create();

                // 开辟一块内存流，存储密文
                using MemoryStream Memory = new MemoryStream(encryptedBytes);
                // 把内存流对象包装成加密流对象
                using CryptoStream Decryptor = new CryptoStream(Memory,
                Aes.CreateDecryptor(bKey, bVector),
                CryptoStreamMode.Read);
                // 明文存储区
                using MemoryStream originalMemory = new MemoryStream();
                byte[] Buffer = new byte[1024];
                int readBytes = 0;
                while ((readBytes = Decryptor.Read(Buffer, 0, Buffer.Length)) > 0)
                {
                    originalMemory.Write(Buffer, 0, readBytes);
                }

                original = originalMemory.ToArray();
            }
            catch
            {
                return null;
            }
            return Encoding.UTF8.GetString(original);
        }
    }
}
